1. Field of the Invention
The present invention relates to improvements in a Cardan-type universal joint.
2. Description of the Prior Art
A prior Cardan-type non-constant angular velocity universal joint is publicly known through such information as disclosed in Japanese Patent Unexamined Publication No. (JP-A) HEI-3-74632.
The universal joint publicly known as above has a pair of joint bodies each comprising a cylindrical hub to be secured to a rotary shaft, and two yokes protruding in the axial direction from one end of the hub at two circumferential positions mutually oppositely disposed in a radial direction of the hub toward the other joint body. The hub and the yokes of each of the joint bodies are formed together into a single component part.
The universal joint publicly known as above also has a cross-shaped member comprising four pins protruding radially therefrom in a cross-shaped manner such that the pair of joint bodies are connected with each other at a phase difference angle of 90 degrees by having each of the pins supported with bearing means at a corresponding one of the yokes of the pair of joint bodies. The bearing means has a bearing hole disposed radially at and through the front end portion of each of the yokes, the bearing hole having an oilless-metal sleeve pressure-fitted and secured therein. The cross-shaped member further comprises a short column-shaped center piece having four circumferentially spaced pin holes formed radially therein, the center piece having the pins respectively slidably and rotatably inserted through the sleeves of the yokes and pressure-fitted in the pin holes such that the pair of joint bodies are coupled together through the cross-shaped member so as to constitute the universal joint.
Although the prior Cardan-type universal joint publicly known as above is capable of absorbing angular deflection and eccentricity between two rotary shafts secured to the joint, the prior joint has a disadvantage in that it is not suitable for coupling rotary shafts that are displaced axially by axial load since the prior joint does not have escape means between the hub and the rotary shaft against such axial displacement. The present invention is made to solve such a problem.